Blackcurrant supplementation on sporting performance in adolescent hockey players

In this nutritional intervention study, we aimed to examine how timed blackcurrant supplementation prior to each training session or game influenced the health, physical and cognitive performance parameters of adolescent field hockey players over an 8-week training period. The blackcurrant (freeze-dried powder) supplement used in this study was enriched with anthocyanins (30%) and was from a commercial supplier (Just-the-Berries, Nelson, New Zealand). The participants were given the blackcurrant extract (equivalent 150 mg anthocyanins) as a small opaque gelatine capsule and asked to consume the supplement 1 hr prior to each training session (4 per week) or hockey game (1-2 per week) over the 8-week period. Compliance was monitored by (i) providing particpants with only enough capsules (placebo or blackcurrant) for a week to ensure that the treatments are being taken (ii) notify the trial co-ordinator by text each time they took their treamtent, and (iii) trial coordinator reminded the particpants. In this study, the trial coordinator for this trial was also a hockey coach and so monitored the participants closely. Participants were asked to maintain their normal eating habits but to omit dietary supplements high in antioxidants over the 8-week period. In addition, trial participants were assessed (a) prior to and after an 8-week training periods and (b) weekly (on the same day each week) for their (i) fitness, (ii) cognitive “smart game” skills, and (iii) health.